6L80 Troubleshooting PT2 - Internal Mode Switch
ฝัง
- เผยแพร่เมื่อ 8 ก.ย. 2024
- In this second installment of my GM 6L Diagnosis and Troubleshooting series, I do a deep dive into the internal mode switch (IMS), where I go over what it is, how it works, what can happen when it malfunctions and how to confirm or deny it has failed via continuity testing.
The most serious type of IMS failure will produce a no-crank, no-start condition.
Reference Chart: docs.google.co...
ATSG Manual: atoc.ru/upload...
How do you diagnose if you have an intermittent? I have a p182e when in D. 2014 gmc goes to limp 5th gear. I restart and it resets. On scan tool I observe while driving all 4 channels go to high volt momentarily and I loose red gear indication on dash. Truck goes to limp. Funny thing I can drive in manual mode all day and no problems. D is bad. Trying to figure out if this is the TECHM or the mode switch. Appreciate your video. Park/neutral is fine. Always restarts.
Hi PDaddy - Code P1825 is for the internal mode switch. Additionally, the TEHCM doesn't report your gear/range position to the dash indicator, the mode switch does so I'd say your mode switch is going bad. The fifth channel, Channel N is what reports P/N signal to the PCM directly so if that fails, you will no longer be able to start the vehicle.
You can drop the pan and perform the testing that I demonstrate in the video to confirm or deny, that is what I'd do next. I'd grab a new IMS before doing so - this way you can swap it in...You will also need a Snap On 10EPL socket so you can remove the 'starfish' bolt that secures the IMS to the rest of the assembly (the other bolt takes a conventional 8mm hex socket).
@@nickstransmissions He asked about P182E (which I have the same ), any suggestion? Thank you
Yes, follow the test procedure outlined in the video and replace the IMS if it fails those tests (see the description to links for the ATSG manual and my reference document to help you.
The code is indicating an invalid range setting (ie it's not sending valid range selection).
Awesome info.Thanks man!!
Thanks, HMG!!
What socket is needed to remove the IMS?
You'll need an inverted torx E12 or Snap On 10EPL. You can find them on eBay for about $10
no link to the document?
It's there now along with a link to the ATSG manual.
Wow, thanks for the link. Much appreciated
@@nickstransmissions thanks
07 Escalade..code p0700?
That's a general communication error code associated with the transmission's TEHCM, instructing you to scan and diagnose the transmission for problems.
Are you having drivability symptoms?
yes
my fluid is dirty as well..
What are the symptoms?
Dirty fluid is usually indicative of quite a lot of burnt clutch material present which likely means it's time for an overhaul.
I can count on one hand how many of these I have seen fail. If a unit experiences a very bad torque converter failure it can cause a P182E if not cleaned properly and then reused.
Yea, not a common failure point but I still replace for piece of mind. Plus if it does happen to fail, I can tell the customer (and show proof) it was replaced and failed beyond my control.
Are these susceptible to heat at all? Had a P1825-00 fault code after driving around and giving the car a bit of boogie through the city for a few hours. Cleared the code, and it came back alm,ost instantly, confirming the code. The box basically locked the forward gear to 1 single gear, was able to select park, reverse, and forward essentially. I was able to limp the car home no issues. 2 hours later, start the car, cleared the code, and it has not had a fail since.
I am suspecting either a heat-issue causing the module to fail, or a dodgy loom somewhere.
Sidenote: The car has always has a 1st to 2nd gear switch lag or delay, I would liken it to souond/feel similar to someone that drives a manual and takes 2-3 seconds with the clutch during a change, the revs drop, the engine quietens, the car slows slightly, then you feel it select 2nd and everything comes to life again. I suspect also a mode-switch issue (potentially) but on this one I have no idea.
P0700 and p2714 after a complete new rebuild no reverse stuck in first gear 07 yukon denali
What happened did you figure it out ?
@4-matic212 no not yet
@@durellmchenry969 you replaced this internal switch ?
@4-matic212 what switch u referring to
@@durellmchenry969 the one in this video